1. Field of the Invention
The present invention relates to a motor driving apparatus and a method of controlling the driving of a motor by accurately detecting a rotation position of the motor.
2. Description of the Related Art
A brushless direct current (BLDC) motor generally refers to a DC motor changing a function of conducting current or adjusting a current direction using a non-contact position detector and a semiconductor element rather than using a mechanical contact such as a brush, a commutator, and the like, in a DC motor according to the related art.
In order to drive this BLDC motor, a driving apparatus may be used.
FIG. 1 is a configuration diagram of a general motor driving apparatus.
Referring to FIG. 1, a general motor driving apparatus 10 may include a controlling unit 11 and a driving unit 12.
The controlling unit 11 may control driving of the motor, and the driving unit 12 may drive the motor by turning four field effect transistors (FETs) on or off in response to a driving signal of the controlling unit 11.
FIG. 2 is a diagram showing driving signals of the motor driving apparatus.
Referring to FIG. 2, the driving signals transferred from the controlling unit 11 to the driving unit 12 may be divided into four kinds of signals, and be transferred in a sequence of identification numerals {circle around (1)}, {circle around (2)}, {circle around (3)} and {circle around (4)}.
That is, a first PMOS FET P1 and a second NMOS FET N2 may be turned on by a driving signal represented by identification numeral {circle around (1)}, and the first PMOS FET P1 and the second NMOS FET N2 may be turned off and a second PMOS FET P2 and a first NMOS FET N1 may be turned on by a driving signal represented by identification numeral {circle around (2)}.
Again, the second PMOS FET P2 and the first NMOS FET N1 may be turned off and the first PMOS FET P1 and the second NMOS FET N2 may be turned on by a driving signal represented by identification numeral {circle around (3)}, and the first PMOS FET P1 and the second NMOS FET N2 may be turned off and the second PMOS FET P2 and the first NMOS FET N1 may be turned on by a driving signal represented by identification numeral {circle around (4)}.
As described above, the cases in which the first PMOS FET P1 and the second NMOS FET N2 are turned on and the second PMOS FET P2 and the first NMOS FET N1 are turned on are repeated, to change a direction of current flowing in the motor, whereby the motor may rotate.
In this driving scheme, when the first PMOS FET P1 or the second PMOS FET P2 is turned on, a pulse width modulation (PWM) signal (oblique line portions of FIG. 2) is generated, whereby a speed of the motor may be controlled.
However, as disclosed in the Related Art Document, Korean Patent Laid-Open Publication No. 10-2005-0082607, the motor driving apparatus according to the related art may not accurately detect a rotation position of the motor, such that it maybe difficult to accurately control the motor. Further, in order to accurately control the rotation position of the motor, a number of hall sensors are required, such that manufacturing costs are increased.